Crystallographic evidence for two-metal-ion catalysis in human pol η.

ABSTRACT: Extensive evidence exists that DNA polymerases use two metal ions to catalyze the phosphoryl transfer reaction. Recently, competing evidence emerged, suggesting that a third metal ion, known as MnC, may be involved in catalysis. The binding of MnC was observed in crystal structures of the replication complexes of human polymerase (pol) η, pol β, and pol μ. Its occupancy (q_MnC ) in the pol η replication complexes exhibited a strong correlation with the occupancy of the formed product pyrophosphate (q_PPi ), i.e., q_MnC ∝ q_PPi . However, a key piece of information was missing that is needed to distinguish between two possible sequences of events: (i) the chemical reaction occurs first with only two meal ions, followed by the binding of MnC in a "catc

SUBMITTER: Wang J 

PROVIDER: S-EPMC6319759 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature